There are a number of ways to make soap. I will talk about the method I use as this is a rather large topic and there are so many methods out there to make soap. The method I used is called cold process.
First I need to mention about safety. Safety is the utmost important thing to follow when making soap. Anyone who makes soap has to wear safety gear (goggles, gloves, long sleeves, pants, and shoes). Only then do I proceed to make soap.
I place a copy of the recipe close by so I can refer to it and make any notes along the way. I gather all the ingredients then weigh what I need. The next step is to prepare the sodium hydroxide (lye) and water. I slowly pour the sodium hydroxide (lye) into water. I stir the lye water in a well ventilated area. Once the lye crystals are dissolved I set this aside and let it cool. Making soap is very much like baking a cake. It's all up to the creator in what ingredients the recipe has. While the lye water is cooling I then weigh and measure the remaining ingredients.
I separate the hard oils and the liquids together. I melt the hard oils first then add that to the liquid oils. As soon as the temperature of both of these are at the temperature I want I pour the lye/water into the oils slowly. Note that each recipe has different ingredients so the steps may be slightly different but the principle of sodium hydroxide being introduced to a liquid is the same. After the lye/water and oils/butters have been blended for awhile the ingredients will reach an emulsion. At that time I add any additives for example: clays, colloidal oatmeal, essential oils and or fragrances.
The next step is to pour this into a mold. This is where the magic begins and the ingredients start to become saponified and turn into soap. The soap is covered and put in place where it's not disturbed and remains in the mold anywhere from a few hours to 2 -3 days again depending on the recipe. The soaps are then taken out of the mold(s) or maybe cut into bars. The soaps are cleaned then put in a place to cure for 4 to 6 weeks. The curing stage allows the water to evaporate making them to be a nice hard bar. There you have it this is basically what I do for making soap.
How I Make Cold Press Soap